Carburetor



Jan, 24, 1928., 1,657,361

' A. M. ALEXANDRESCU CARBURETOR Filed July 1925 3 Sheets-Sheet 1 IN VENTOR fllexandrewzz,

' ATTORNEKYI A. M. ALEXANDRESCU CARBURETOR Filed July 2 1925 3 s t -s t2 iii gunman" INVENZ'OR mndrarcu 3 Sheets-Sheet 5 A. M. ALEXANDRESCUGARBURETOR Filed July 23. 1925 Jan. 24, 1928.

TTORNYS.

Patented Jan. 24, 1928. 7

UNITED STATES PATENT OFFICE.

ALEXANDER m. ALEXANDRESGU, 0E oLEvELAND, OHIO, ASSIGNOR TO THE ALExCORPORATION, or CLEVELAND, OHIO, A conro m'rron OF OHIO.

CARIBURETOR.

The present invention relates to improvements 1n carburetors, and hasfor an obect to provide an improved carburetor 1n which a more thoroughand intimate mix-' ture of the fuel and air will be promoted, andwherein the vapor in the gasoline tank is utilized for forming thecombustible charge instead of being wasted as. under the presentpractice.

A further object of the invention resides in a greater economy in theuse oflthe gasoline, because of this very thorough mixture including theutilization of the gasoline tank vapor.

One of the greatest advantages of the improved carburetor is the greateconomy effected by passing the air above the float in the float chamberthrough a small opening, thereby driving the vapor out from the gasolinefloat chamber. This vapor is drawn into'the carburetor by the suction ofthe motor. 4

The air that drives the vapor from above the float yields approximatelyfifteen miles more per gallon of gasoline. The great amount of vapor(atmospheric gas) that every carburetor at the present time is wastingfrom above its float chambenthrough the breathing hole is thus saved.

A great advantage secured by the 1mproved atomizing or pulverizingsystem. is the preventing of scoring; in other words, no raw gasoline ispermitted .to enter the cylinders of the motor to cut off thelubrication to the pistons, rings and walls of the cylinders. V c

A further objeotof the invention is to provide an improvedcarburetorwhich will secure quick starting of the motor and-at the sametime preventing flooding of the carburetor.

" Further objects of the invention are to avoid smoky exhausts, thereduction and elimination of carbon deposits in the motor,

' greater power from the ignition of the mixture in the motor, andgenerally to secure,

more responsive action in the motor and the prevention of the burning ofthe valves.

With the foregoing and other objects in view, the invention will be morefully de scribed hereinafter, and will be more particularly pointedoutin the claims appended hereto.

In the drawings, wherein like symbols refer to like or correspondingparts throughout the several'views,

Figure 1 is atop plan view, with parts shown in section, of an improvedcarburetor constructed according to my present invenion.

Figure 2 is a vertical section taken longitudinally on the line 2-2 inFigure 1.

Figure 3 is a cross section taken on the line 33 also in Figure 1.

Figure 4 is a horizontal section taken on the line 4-4 in Figlire 2.

Figure 5 is a similar section taken on the hue 5-5 in Figure 2.

Figure 6 is a longitudinal vertical Section taken on the line 66 inFigure 1.

Figure 7 is a vertical section taken on the line 7-7 in Figure 1, andadditionally showing the gasoline tank in vertical section.

Figure 8 is a side view of the needle valve on an enlarged scale.

Figure 9 is a vertical section showing the atomizing tube taken on anenlarged scale. Figure 10 is an'enlarged elevation of the atomizingsleeve.

Figure 11 is a section taken on the line 1 111 in Figure 10, and

Figure 12 is a perspective view of a valve employed.

Referring to Figure 7, 14 designates the gasoline tank usually at therear of the automobile, or other vehicle upon which the improvedcarburetor is installed. This asoline tank is provided with the usualfil ing neck 15 closed 10 the screw cap 16 having the usual vent 1Usually the gasoline is taken from the bottom of the tank to a vacuum-.tank and the connection for this purpose is indicated at 18. The-liquidgasoline v is pulled from the tank 14 by the vacuum in the vacuum tankand is then circulated to the carburetor. the vacuum tank has been leftout, and in Figure 3 the pipe 18 is-shown as connected through the sidewall of the shell 19 of the carburetor. Many automobiles do not use thevacuum tank and. in this case the pipe 18 will extend directly to thecarburetor. A passage 20 in the shell places the gasoline incommunication with the float chamber 21.

The float valve 22 controls the entrance of the gasoline to the floatchamber and this valve is under the control of the float 23 hinged asindicated at 24 to a bracket or For purposes of clearness other support.The float rises with the liquid gasohne in the float chamber and "closesthe valve 22, thereby avoiding flooding of the carburetor in accordancewith a well known practice. Again adverting to Figure 7 a dome is madeabove the gasoline tank at a convenient point, and is in communicationby means of the perforations 26 in the top of the tank with the vaporspace above the gasoline body, whereby this vapor may be collected inthe dome and circulated through the pipe 27 to the carburetor. As shownin Figures 1 and 7 this pipe 27 introduces the gasoline vapor to thespace directly in advance of the throttle valve 28.

As shown in Figures 3 and 6 the gasoline from' the float chamber 21passes through the screen 29 and into the hollow column 30 through theperforations 31. From this point the liquid gasoline ascends into thenozzle 32, which is provided at the base with the threaded enlargement33 for screwing into the column 30. There is a slot 34 in the base ofthe nozzle for the urpose of screwing the nozzle in and out o thecolumn. The nozzle is provided at its upper end with a conical or flaredseat 35 for the point of the needle valve 36. The needle valve may beoperated by the hand piece 37 shown in Figure 8 directly above thecarburetor or by the connection indicated at 38, in Figure 6, whichextends to the instrument board of the vehicle.

The needle valve 36 is provided with the screw threads 39 in the bodythereof, which take into similar threads 40 in the passage down throughthe top of the carburetor shell provided to receive this needle valve.By the turning of the valvein either direction the point 41 of the valveis moved toward or from the seat 35 in the nozzle 32 and the flow ofgasoline is regulated in the usual less numbers. The shoulders are shownas pinges to there being annular and as interposing progressivel widerabutments for the ascending aso 'e to strike against. The shouldersormtargets against which the gasoline imy break up the gasoline andatomize the same.

The gasoline is formed into a spray or mist by this practice'and theseshoulders or abutments are arranged directly in the path of the air, andthe shouldered portion of the needle is housed within a sleeve 43,shownparticularly in Figures 10 and 11. This sleeve is open at its bottom andsurrounds the nozzle. It is also open at its top portion to slip aboutthe needle valve and to permit the needle valve to turn therein. Thesleeve may be fitted frictionally in the needle opening of thecarburetor and in the hollow post 30, or it maybe held therein in anyappropriate manner. At the air side of the carburetor the wall of thesleeve is provided with a number of perforations 44. all exposed to thein rushing air. These perforations are arranged opposite the steps ofthe needle, so as to direct the air in minute I streams to the gasolineat the point of impact with the shoulders. The side of the sleeve nextthe throttle valve is slotted vertically and provided with teeth orserrations 45 at both vertical side edges of the slot. The points ofthese teeth extend around and the converging side edges of the teeth allform sharp points and edges against which the commingled air andgasoline is made to pass, thus further assisting to break up,

atomize and commingle the air and gasoline. The shoulders 42 of theneedle valve will direct the gasoline laterally and horizontallyrepresents a plug having a socket 91 to receive a coil spring 92 and afriction shoe 93 which conforms at its outer edge to the bearing portionof the choke valve and is urged against this choke valve by the coilspring. Plug 90 is held by the rivets 94, shown in Figures 1 and 6, tothe cover plate '95. In turn this cover plate 95 is removably secured tothe carburetor shell by the screws or other fastenings 96. This frictionshoe, under tension of the spring, will preventthe choke valve fromvibratin and chattering, compelling the choke va ve to undergo -acomparatively slow movement in opening and closing. The choke valve 47is operated by thesuction of the motor. according to the opening andclosing of the throttle valve 28. The weight or gravity of thechokevalve controls the suction of more or less fuel and the vapor fromthe gasoline tank and float chamber. Observe in Figure 6 the two linesindicating the tilted position of the carburetor in going up and downgrade. In going up grade, weight of the choke valve will act moreeffectively against the suction of the motor, thus making it morediflicult to open the choke valve and requirin a greater amount ofsuction to do this wor k. Consefluently, a richer mixture will be drawnfrom sition illustrated. As shown in Figure 6,

the carburetor nozzle and from the two vapor sources. In going downhill,when the motor is under less load and strain, the carburetor is sotilted that the choke valve 47 will open upon a comparatively lightsuction and the mixture will thus be diluted and considerable gasolinesaved by this automatic performance of the choke valve. When the chokecontrol lever 51, which is normally held by the spring 52, against thestop 53, is pulled in the direction of the arrow, shown in Figure 2, thescrew 50 is moved down against the shoulder 54 (Figure 6) of the chokevalve. In this case the valve 47 cannot be lifted, because the head ofthe screw 50 acts as a stop. The screw head is moved-to the positionjust referred to when starting the cold motor in order to draw a richmixture to the engine. An air by-pass 55 is made in the shell of thecarburetor paralleling the carburetting chamber. Air is supplied to thispassage through the opening 56 which is outwardly of the choke valve(see Figure 6). The by-pass 55 is adapted to convey air through thepassage 57 to the vapor space in the float chamber 21. The gaseous vaporpicked up by the air circulating over the body of fluid in the floatchamber is conveyed off from the float chamber by the passages 58 and 59to thev carburetting chamber adjacent the throttle valve 28. Thesepassages are shown in Figures 4, 5, 6 and 7 The mixture of air and fuelvapor gives a quick start to the engine in the coldest weather andprevents raw gasoline from entering the cylinders thatfloods the motor,destroying it, causing scoring of the cylinders, etc.

The by-pass' 55, as shown in Figure 3, connects by the downwardlyextending'passage 60, with the space about the nozzle 32. The nozzle issmaller than the sleeve 43 and forms an annular air passage w ere thenozzle extends up into the lower. pq' tion of the sleeve. The sleeve isfrusto-conical thus increasing the velocity of the air which ascendsfrom the base of the nozzle, and causes the air to pick up the "gasolinefrom the top of the nozzle as governed by the position of the needlevalve. p I

The by-pass 55 further communicates by a passage 61 of small crosssectional area with a larger passage 62 connecting with the duct 63which carries the air about the throttle valve 28. The by-pass will thusfurnish air directly to the engine whenever pumping action takes placetherein, through the small cross sectional area passage 61. The passage61' is, however, by-passed by the passage 64 controlled by the valve 65which valve is shown in Figure 12. The valve is carried be lifted to thecombustion chambers,

down upon the wall of the passage-64 and act as guides for the valve,while the upper wider portion of the tip seats against the bottom of thepassage 64. The stem 66 slides in the hollow cap 68, shown in Figure '2,and a coil spring 69 wound about the valve stem urges the valve to aclosed position.

The air will enter through the passage 56, without regard to the closedposition of the choke valve 47 and entering the by-pass 55 will bedistributed to the three places above mentioned. That air which goes tothe float chamber will result in the formation of a mixture of air andfuel vapor which is circulated to the motor through the openings 58 and59. That air which descends through the passage will be lifted about thenoz-.

zle drawing the gasoline upwardly therewith through the nozzle. Thisgasoline and air will impinge a ainst the shoulders of the needle valvewithin the circumscribed space of the sleeve 43. This mixture ofgasoline and air will be broken up and atomized as hereinbeforeexplained, and will bedrawn into the motor, mixing with the vaporizedfuel ascending throu h the perforators 58 and 59 and also with thevapor. from the gasoline tank. This forms a very rich mixture, which is,very effective in starting the motor in the coldest weather,

Ordinarily the spring 69 will be of a strength to keep the valve closed,so that no air will pass throu h the relatively large passage 64 whichpara lels the restricted passage 61. However, if the operatorinadvertently omits to turn on the switch and keeps the starter inoperation for some time, the tendency will be to create a degree ofvacuum which is undesirable as drawing up oil from the crank case pastthe pistons to relieve this vacuum.

It is the purpose of the valve 65 to provide an easier andquicker relieffor any abnormally strong vacuum produced in the motor at this time. Thespring "69 will be selected as of a strength to meet these conditionsand to permit opening of the valve and the supply of thevacuum-breaking'air invalve 65 maybe described as followsz'forfloperating thecar at high speed and necessity demands a quick stop, the oerator will close the throttle valve 28 first y removing the brakeoperating foot from the throttle control and afterwards releasing theclutch the oilfrom the crank ease up about t e pistons and into thecombustion chambers. This is, of course, disadvantageous. In accordancewith the present invention, under the conditions just noted, the valve65 will open in obeyance to this great suction and will relieve it withatmospheric air before 'also tends to rotate the she the oil can bedrawn up about the piston rings. The valve does not yield readily andconsequently opens only when the suc-- tion increases to a high degree,such as is sufficient to draw the oil in the crank case past thepistons. The braking eflect ofthe engine, turned over by the momentum ofthe vehicle, is not lessened up to this high suction.

Most drivers at the present time will leave the clutch in when runningdown grade, although the throttle valve is closed. The compression ofthe engine is used to brake the car. This is another situation in whichthe unrelieved suction in the motor tends to draw up oil from the'crankcase above the pistons. To remedy this situation, the valve 65 in theimproved carburetor will open to relieve this vacuum.

At 99 is shown a cotter pin for holding the shaft 48 permanently inplace. spring 52 urges the shaft long'tudinally and The cotter pin 99prevents the spring 52 from ejecting the shaft from the carburetor.

Air is constantly entering the-gasoline tank 14 through. the vent l7 andthrough the filling neck 15. This air absorbs the vapor in the upperpart of the tank and the vapor is drawn to the carburetor under theoperation of the throttle valve.

In addition the "vapor from the gasoline tank at the rear of theautomobile is furnished through the pi the throttle valve, so t at Iprovide a three fold source of mixture, one from the gasoline tank atthe rear of the automobile, secondly from the float chamber of thecarburetor, and thirdly from the nozzle of the carburetor. Thesecombustible vapors, ordinarily wasted are thus utilized to the economyof the mixture requiredto be furnished at the nozzle of the carburetor.

It is obvious that various 'changes and modifications may be made in thedetails of construction and design of the above specifi The 27 at apoint near cally described embodiment of this invention withoutdeparting from the spirit thereof, such chan s and modifications beingrestricted only y the scope of the following claims What is claimedis 1. A carburetor comprising a shell having a carburetting chamber, afuel supply nozzle opening into said carburetting chamber, a pluralityof consecutively step ed bafiie means for interrupting and de ecting theflow of fuel from the nozzle, and a separate air supply means for anddisposed opposite to each of said bafile means for admixing airseparately and intimately with the fuel at each point of interruptionand deflection of the latter.

2. A carburetor comprising a shell having a carburetting chambertherein, a fuel nozzle opening into the carburetting chamber, a valvefor controlling said nozzle and having a plurality of stepped shouldersfor interrupting and deflecting the fuel enters ing the carburettingchamber, and means for supplying separate iets of air independently tothe stepped shoulders for intimately admixing the air with the fuel atthe points of interruption and deflection thereof as the fuel enters thecarburetting chamber.

3. In a carburetor having a fuel nozzle and a needle valve controllingthe fuel nozzle and provided with stepped shoulders out wardly thereofto receive and deflect fuel issuing from the nozzle, an air distributingtube surrounding the needle valve and having air admission openingsarranged in alinement with said stepped shoulders and provided at oneside with a longitudinal slot exposing the needle valve, the marginaledge portions of the tube at said, slot being serrated to break u andcommingle the separate streams of air from the openings in the tube andthe separate streams of fuel deflected from said stepped shoulders.

4. A carburetor comprising a casing having a mixing chamber therein,throttle and choke valves means for supplying a mixture of air. and fuelto said mixing chamber, a byass extendin about said throttle and cho evalves an said mixture supplying means, saidby-pass having a portion ofrestricted cross sectional area, a secondary b pass of larger crosssectional area within the first by-pass, and a valve operated only by ahigh suction for said secondary by- P ALEXANDER M. ALEXANDRESCU.

